Highly Sensitive Detection of Iron Ions in Aqueous Solutions Using Fluorescent Chitosan Nanoparticles Functionalized by Rhodamine B

Abstract

Detection of iron ions in aqueous solutions is of significant importance because of their important role in the environment and the human body. Herein, a fluorescent rhodamine B-functionalized chitosan nanoparticles probe is reported for the efficient detection of iron ions. The chitosan nanospheres-rhodamine B (CREN) was prepared by grafting rhodamine B onto the surface of chitosan nanospheres through an amidation reaction. The as-prepared CREN fluorescent probes exhibit high fluorescence intensity under ultraviolet light. When iron ions are added to the CREN solution, they can be coordinated with weak-field ligands such as N and O on the surface of chitosan nanoparticles (CSNP) by a high-spin method. The self-assembly of Fe 3+ on the surface of the CREN led to the generation of single electrons and the presence of high paramagnetism, resulting in fluorescence quenching. The quenching effect of Fe 3+ on the CREN fluorescent probe can achieve the efficient detection of Fe 3+ , and the detection limit reaches 10 −5 mol/mL. Moreover, this fluorescence quenching effect of Fe 3+ on the CREN fluorescent probe is specific, which could not be disturbed by other metal ions and counteranions.

Chitosan-bodipy macromolecular fluorescent probes prepared by click reactions for highly sensitive and selective recognition of 2,4-dinitrophenylhydrazine

“…29 In addition to the pharmaceutical and food industries, chitosan has also become increasingly important in the field of fluorescent probes. 30,31 When fluorescent units are introduced to chitosan, high potential application value will be obtained. Fluorescent groups such as BODIPY, naphthalimide 32 and coumarin can be introduced to form different chitosan based fluorescent probes through the Schiff base formation reaction 33,34 and the acylation reaction 35 of the active amino groups on chitosan.…”